package com.heima.kafka.sample;

import org.apache.kafka.clients.consumer.*;
import org.apache.kafka.common.TopicPartition;

import java.time.Duration;
import java.util.Collections;
import java.util.Map;
import java.util.Properties;

/**
 * 消费者
 */
public class KafkaStreamConsumerQuickStart {

    public static void main(String[] args) {

        //1.添加kafka的配置信息
        Properties properties = new Properties();
        //kafka的连接地址
        properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "192.168.200.130:9092");

        //消息key和value的反序列化器
        properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");
        properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");

        //消费者组
        properties.put(ConsumerConfig.GROUP_ID_CONFIG, "group1");

        //手动提交偏移量
        properties.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG,false);

        //2.创建kafka的消费者对象
        KafkaConsumer<String,String> kafkaConsumer = new KafkaConsumer<String, String>(properties);

        //3.订阅主题
        kafkaConsumer.subscribe(Collections.singletonList("itcast-topic-out"));

        //4. 拉去消息
        while (true) {
            ConsumerRecords<String, String> consumerRecords = kafkaConsumer.poll(Duration.ofMillis(1000));
            for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
                System.out.println("分区: "+consumerRecord.partition());
                System.out.println("偏移量: "+consumerRecord.offset());
                System.out.println("key: "+consumerRecord.key());
                System.out.println("value: "+consumerRecord.value());

                //同步提交异常
                /*try {
                    kafkaConsumer.commitSync();
                } catch (Exception e) {
                    System.out.println("记录提交失败的异常："+e);
                }*/

            }
            //异步提交
            kafkaConsumer.commitAsync(new OffsetCommitCallback() {
                @Override
                public void onComplete(Map<TopicPartition, OffsetAndMetadata> map, Exception e) {
                    if (e!=null){
                        System.out.println("记录错误的提交偏移量"+map+"，异常信息"+e);
                    }
                }
            });

        }
    }

}